Change Hostname on Debian/Ubuntu

Sometimes happen you want to change the hostname for your machine. Debian based systems (Debian/Ubuntu) have the hostname information saved in this file /etc/hostname . This is the file location from where the system at the boot time is reading and set it up using the init script that is located in /etc/init.d/hostname.sh .

You can edit the file /etc/hostname very easy and apply your desired change for hostname on the system

Steps:

sudo gedit /etc/hostname

make the change of hostname and save the file

sudo /etc/init.d/hostname.sh start

All changes are now applied and you should have now a new hostname on the system. To verify that the changes really have taken place run these commands:

sudo hostname {shows the current hostname on the system}

sudo hostname -f {shows you hostname.localdomain information}

sudo hostname -d {shows you localdomain information }

sudo hostname -i {shows ip address for the hostname}

If any of the information for localdomain does not match you can edit/correct this information in this file /etc/hosts

To make changes in /etc/hosts:

cd /etc

sudo gedit hosts

make the correct changes {127.0.0.1 hostname and 127.0.0.1 hostname.localdomain}

save the changes

Additional switches for hostname are:

-s = short hostname

-a = alias name

-i = ip address for the hostname

-I = all ip addresses for the hostname

-d = domain name for the hostname

-f = FQDN, all long hostname

Now you re-run the commands: hostname, hostname -i, hostname -d and hostname -f — you should have now the correct hostname and localdomain on your system